Modeling and vibration analysis of drilling bit and effect of different parameter’s on it’s optimal operation in stick/slip case

Ali Makvandi¹

1) Iran University of Jami

IOI Code : XBFB-DEHBH
Publication : International Congress On Engineering, Technology and Innovation(eticong.com/1st)
Abstract :
    The undesired stick-slip vibration is the main source of PDC bit failure, such as tooth fracture and tooth loss. Therefore, the study of PDC bit failure base on stick-slip vibration analysis is crucial to prolong the service life of PDC bit and improve R.O.P(Rate Of Penetration). For this purpose, a piecewise-smooth torsional model with 4-DOF(degree of freedom) of drilling string system improper PDC bit is proposed to simulate non-impact drilling. In this model, both the friction and cutting behaviors of PDC bit are innovatively introduced. The results reveal that PDC bit is easier to fail than other drilling tools due to the severer stick-slip vibration. Moreover, reducing W.O.B(Weight On Bit) and improving driving torque can be effectively mitigate the stick-slip vibration of PDC bit. Therefore, PDC bit failure can be alleviated by optimizing drilling parameters. In addition, a new 4-DOF torsional model is established to simulate torsional impact drilling and the effect of torsional impact on PDC bit’s stick-slip vibration is analyzed by applying an engineering example. It can be concluded that torsional impact can mitigate stick-slip vibration, prolong the service of PDC bit and improve drilling efficiency, which is consistent with the field experiment results.

Keywords : drilling drill string drill bit drilling vibration’s stick/slip vibration